Aung San Suu Kyi says she believes Myanmar will hold full democratic elections in her lifetime.
She told the BBC she does not know when that would be or whether she would run.
Ms Suu Kyi, 66, is due to meet William Hague, the first British foreign secretary to visit since 1955.
He is calling on Myanmar's leaders to hold free elections and release political prisoners.
A nominally civilian government is now in place in Myanmar. It is led by President Thein Sein, a former general.
Ms Suu Kyi said: ''I trust the president, but I can't yet trust the government for the simple reason that I don't yet know all the members of government.''
She added: ''The most important thing about the president is that he is an honest man ... He is a man capable of taking risks if he thinks they are worthwhile.''
The National League for Democracy was formally registered as a political party last month, after boycotting the 2010 polls because of electoral laws that prevented Suu Kyitaking part.
Registration of the NLD was officially approved on Thursday.